3 ideas
| 8920 | Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz] |
| Full Idea: A relation R on a non-empty set S is an equivalence relation if it is reflexive (for each member a, aRa), symmetric (if aRb, then bRa), and transitive (aRb and bRc, so aRc). It tries to classify objects that are in some way 'alike'. | |
| From: Seymour Lipschutz (Set Theory and related topics (2nd ed) [1998], 3.9) | |
| A reaction: So this is an attempt to formalise the common sense notion of seeing that two things have something in common. Presumably a 'way' of being alike is going to be a property or a part |
| 16627 | If you remove the accidents from a horse and a lion, the intellect can't tell them apart [Francis of Marchia] |
| Full Idea: Let all accidents be removed from a lion and a horse. Nothing remains in the intellect to distinguish them. We distinguish a lion and a horse only by analogy to the accidents proper to each. The intellect does not have an essential concept of either one. | |
| From: Francis of Marchia (Commentary on Sentences [1330], I.3.1), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 07.3 | |
| A reaction: What a very nice thought experiment, and very convincing about how the mind perceives such things. But we don't believe horse and lion just consists of the surface properties of them which we experience. |
| 3029 | Stilpo said if Athena is a daughter of Zeus, then a statue is only the child of a sculptor, and so is not a god [Stilpo, by Diog. Laertius] |
| Full Idea: Stilpo asked a man whether Athena is the daughter of Zeus, and when he said yes, said,"But this statue of Athena by Phidias is the child of Phidias, so it is not a god." | |
| From: report of Stilpo (fragments/reports [c.330 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.10.5 |